Biomechanical changes and associated factors of preserved SMILE-derived corneal stromal lenticules.

OBJECTIVES

To investigate the biomechanical changes and associated factors of SMILE-derived lenticules under various preservation conditions.

METHODS

A total of 520 corneal stromal lenticules of 260 patients (male: female 98:162, age 28.54 ± 5.98 years, mean spherical error -4.47 ± 1.63 D) were derived during small incision lenticule extraction (SMILE) surgeries, and were stored in glycerol, silicone oil, Optisol and cryopreservation for 1 day, 1 week or 1 month. Spherical error, cylindrical error as well as other main parameters were evaluated. A nanoindenter system was used to measure the effective Young's modulus of each lenticule. Changes in effective Young's modulus were evaluated in each group among all time points.

RESULTS

There was no statistical significance in effective Young's moduli of lenticules in the glycerol group among all preservation times, while the lowest effective Young's modulus appeared when preserved for 1 month, 1 week, and 1 day in the silicone oil, Optisol, and cryopreservation group. Among all factors observed, the spherical error of SMILE-derived lenticules was a positive influencing factor on their biomechanics (P = 0.04*).

CONCLUSIONS

It is feasible to maintain biomechanical stability of SMILE-derived lenticules in glycerol in the short term. Thickness is a positive influencing factor on the biomechanics of SMILE-derived lenticules.